The regulations concerning lighting, for example in the field of road lighting (see for example the standards UNI 10439, UNI 11248, UNI EN 13201-2/3/4), deal with subjects such as the selection of the lighting classes, the needs in terms of lighting, the measurement methods and the calculation of the performances in terms of lighting.
At least at present, however, there are no specific standards relating to the installation geometry, for example in the context of road lighting, in relation to factors such as, for example, the height of the posts, the distance between the posts or the width of the road.
The lack of specific definitions in relation to the mounting conditions, for example in the context of a road, inevitably results in ambiguity in terms of selection and of configuration of the lighting device (luminaire) most suited for lighting a certain roadway. All this with the risk that lighting devices designed according to fixed optical criteria and thus with a certain radiation diagram may be installed in an unsuitable road setting.
To try and alleviate the problem and provide lighting devices able to adapt to different settings, solutions used to date provide, for example, for setting the radiation diagram differently and/or for using different lenses which adapt to the same light radiation source (for example an LED light radiation source) or if need be to a full range of lighting devices.
These solutions are not completely satisfactory, however.
By way of example, the process of tilting the lighting device merely makes it possible to vary the inclination of the radiation diagram, and in some cases there is the risk of causing phenomena relating to dazzling and light pollution of the sky.
The use of lenses makes it possible to keep the light radiation source (for example an LED light radiation source) fixed, thereby making it possible to pass from one radiation diagram to another. On the other hand, lenses, in particular those for outdoor application, are subject to a number of disadvantages, such as for example yellowing due to ultraviolet rays.
Beyond this, the fact that it is necessary to provide an entire range of different devices which satisfy different optical requirements is not particularly efficient in terms of costs when confronted with the possibility of having a modular system.